Changes and clinical significance of invariant natural killer T cells and their subsets in newly diagnosed type 1 diabetic patients

Abstract Objective:The aim of this study was to investigate the changes and clinical significance of the invariant natural killer T(iNKT) cells and their subsets in peripheral blood of newly diagnosed type 1 diabetic patients. Methods: 23 newly diagnosed type 1 diabetic patients and 17 healthy volunteers(from 2015 to 2019)were collected. Peripheral blood mononuclear cells (PBMC) were isolated by FICOII method, the ratio of main cell subsets of PBMC was determined by Flow cytometry. The changes of iNKT cells and their subsets (CD4 + , CD4-CD8-, CD8 + , CD4 + CD8 +) in peripheral blood as well as their correlation with clinical indexes were monitored. Results: Compared with the healthy group, the absolute TCRVβ11+iNKT cell number in the peripheral blood of newly diagnosed type 1 diabetic patients (p=0.03) was significantly higher. The absolute CD4+TCRVβ11iNKT cell number (p=0.00) , CD4+TCRVα24 +iNKT cells (p=0.01) , CD4+TCRVα24J18 +iNKT cells (p=0.00) ,CD8+TCRVβ11+iNKT cells(p=0.021) and CD4+CD8+ TCRVα24+iNKT cells (p=0.002) were significantly increased. The absolute CD4-CD8-TCRVα24+iNKT cell number (p=0.030) in T1DM patients was significantly lower than that in HC. In newly diagnosed type 1 diabetic patients, the absolute CD4+TCRVβ11+iNKT cell number was negatively correlated with BMI (p=0.001, r=-0.492) , and the absolute CD4+TCRVα24+iNKT cell number was negatively correlated with BMI (p=0.014, r=-0.387) , the absolute CD4+TCRVα24J18+iNKT cell number was negatively correlated with BMI (p=0.010, r=-0.402) and positively correlated with glycated hemoglobin (P=0.048, r=0.417). The absolute CD4+CD8+TCRVα24+iNKT cell number was positively correlated with 30 minutes and 1 hour postprandial C-peptide(p= 0.002, r=0.664; p= 0.002, r = 0.669) . Conclusion: Our data indicated a higher absolute iNKT cell number in T1DM patients compared with that in healthy patients, and was accompanied by changes in the number of cell subsets. The immune dysfunction mediated by iNKT cells may associate with the development of type 1 diabetes.